Gas Exchange in Animals

  1. PPO2
    159mm Hg
  2. Fick's law of diffusion
    • Q = DA(P1 - P2)/L
    • Q - the rate at which a substance diffuses between two location
    • D - the diffusion coefficient, dependent on size and shape of diffusing substance, medium, and temperature
    • A - the cross sectional area over which the substance is diffusing
    • P1, P2 - the partial pressure of the gas at two locations
    • L - is the disance between these locations
  3. Adaptions for maximizing respiratory gas exchange
    • Increase the surface area of exchange
    • maximize the partial pressure gradient
    • Proper ventilation of the respiratory medium
    • Proper blood flow on the inside of the respiriatory suface
    • Decrease distance between the two sides of the medium
  4. Air vs. Water breathing
    • Easier to obtain O2 from air than water
    • Air contains 20x more O2
    • O2 diffuses 8,000 times more rapidyly
    • Water breathers must work harder to breathe than air breathers
  5. Temperature Effects on O2 in water
    • As temperatures rise, so does the animal's metabolism and the need for more O2
    • Warm water holds less O2 than cold water
  6. O2 Diffussion in the Organism
    • Because of the slow diffusion of O2 in water, the PPO2 of cells has to be 1-2mm Hg
    • Animals w/o internal transport of O2 are either severly limited in size or have evolved bodies that are flattened or built around a central cavity
  7. Tracheae
    branched tubules in insects used for gas exchange
  8. Gas exchange system
    Gas exchange surface + the mechanisms used to ventilate and perfuse gas exchange surface
  9. Spiracles
    tracheae openings to the outside world
  10. Tracheoles
    branches of the tracheae in insects where O2 is delviered to air capillaries very close to cell mitochondria
  11. Gas Gill/ Plastron
    Bubble of air used by insects for breathing underwater
  12. Hydrofuge
    numerous cuticular hairs on the surface of an insect to maintain a constant gas gill
  13. Gas exchange for fish
    • Gills have high surface area
    • Double pump system for ventilation (mouth and operculum)
    • Constant one-way water flow over the gills maximizes PO2 on the external gill surface
    • Counter-current blood flow maximizes O2 exchanged.
  14. lamellae
    gas exchange surface for gills
  15. Gill arch
    break into gill filaments with lamella on the filaments
  16. Aviary Respiration
    • Air flows unidirectionally through lungs to maximize gradients
    • Air sacs connect to lungs to allow for unidirectional flow
  17. Parabronchi
    further subdivizion of bronchi in birds that run parallel to one another
  18. Alligator respiration
    • One-way air flow but no air sacs
    • Mechanism unknown
    • Reminder: birds and crocodilians evolved from DINOSAURS RAWRRRR!
  19. Tidal volume
    amount of air exchanged in a single breath at rest
  20. Vital capacity
    maximum usable lung volume
  21. Anatomical dead space
    • airways in which gas exchange cannot occur.
    • Residual volume is the air that keeps the lungs from collapsing, part of the dead space
  22. Total lung capacity
    residual volume + vital capacity
  23. How are the ineffeciencies of tidal breathing compensated in mammalian lungs
    • Enormous surface area
    • Short path length for diffusion
  24. Surfactant (lipoproteins)
    A chemical substance that reduces the surface tension of a liquid
  25. Respiratory Stress Syndrome
    • Possible in premaure babies
    • Alveoli don't produce surfactants yet
  26. Intercostal muscle (internal/external)
    lift ribgs up or down to increase thoraic cavity
Card Set
Gas Exchange in Animals
Section 3/3 for Bio Test 3